Hob: Use inherit information to judge if a recipe is image type

Hob: Use inherit information to judge if a recipe is image type

Previously we use pattern "-image-" to match recipe name to judge if
it is image type. This will ignore some images whose name doesn't
match the pattern. The new method is to use the inherit information,
that is, if a recipe inherits image.bbclass, we treat it as an image.

(From Poky rev: 981b81bd39529d2ba9af0d4e2a25bda3d32bd8fc)

(Bitbake rev: bdbee0c899e115ad08b9a77d3e58d6767766da75)

Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>